LEDs are being used with increasing frequency in the lighting industry as a replacement for conventional light sources, such as electric light bulbs and fluorescent light fixtures, for reduced energy consumption and smaller fixture size. Examples of lighting of this type are step lights, emergency lighting and path lighting to identify emergency exit routes as well as lighting installed in the floor for decorative purposes. Furthermore, the LED is becoming increasingly important as lighting to replace conventional room and building lighting. Lights utilizing LEDs arranged on a printed circuit board are known, for example, from DE 10 2004 004 779 or U.S. Pat. No. 7,182,627.
High-output LEDs, as are increasingly being used, however, have higher losses that becomes noticeable in the form of heat. Since LEDs are very heat-sensitive and in particular their service life is reduced by heat, an effective cooling must be ensured. To this end the trend is increasingly to mount the LED on a printed-circuit board, the material of which, for example, aluminum, is a good thermal conductor. The LED mounted on a printed-circuit board of this type is usually mounted on a base forming part of a cooler using a so-called thermal paste. This also ensures an effective heat removal and thus serves as a heat sink.
For specific purposes it has become customary among manufacturers to attach an individual LED on a so-called star circuit board that has contact traces coated with solder. The individual star arms are separated from one another by part-circular sections. Screws extend through them so that the screw heads bear against the printed-circuit board and hold it down on the support body. Electrical hookup cables are soldered onto the contact traces by means of conventional soldering techniques.
The lighting industry, which uses LEDs of this type for production, prefers solderless connection of the hookup cables, since this facilitates assembly and makes it possible to replace defective LEDs easily. A solderless connection technology of this type is disclosed by US 2007/0070631, in which several LEDs mounted on a printed-circuit board can be used by means of suitable connection technology in conventional light fixture holders for fluorescent light fixtures. This solution may be specifically suitable for the replacement of fluorescent light fixture tubes, but is not suitable for other purposes.
Another solderless electrical connection of LEDs in the automotive field is disclosed by US 2003/0183417, which proposes a bayonet-like fixing of an LED, the LED in this case not having a printed-circuit board.
DE 87 11 882 also proposes a solderless electrical connection with an LED without a printed-circuit board.